HiStar is a new operating system designed to minimize the amount of code that must be trusted. HiStar provides strict information flow control, which allows users to specify precise data security policies without unduly limiting the structure of applications. HiStar's security features make it possible to implement a Unix-like environment with acceptable performance almost entirely in an untrusted user-level library. The system has no notion of superuser and no fully trusted code other than the kernel. HiStar's features permit several novel applications, including an entirely untrusted login process, separation of data between virtual private networks, and privacypreserving, untrusted virus scanners.

This paper revisits an old approach to operating system construction, the library OS, in a new context. The idea of the library OS is that the personality of the OS on which an application depends runs in the address space of the application. A small, fixed set of abstractions connects the library OS to the host OS kernel, offering the promise of better system security and more rapid independent evolution of OS components.We describe a working prototype of a Windows 7 library OS that runs the latest releases of major applications such as Microsoft Excel, PowerPoint, and Internet Explorer. We demonstrate that desktop sharing across independent, securely isolated, library OS instances can be achieved through the pragmatic reuse of networking protocols. Each instance has significantly lower overhead than a full VM bundled with an application: a typical application adds just 16MB of working set and 64MB of disk footprint. We contribute a new ABI below the library OS that enables application mobility. We also show that our library OS can address many of the current uses of hardware virtual machines at a fraction of the overheads. This paper describes the first working prototype of a full commercial OS redesigned as a library OS capable of running significant applications. Our experience shows that the longpromised benefits of the library OS approach-better protection of system integrity and rapid system evolution-are readily obtainable.

This paper revisits an old approach to operating system construction, the library OS, in a new context. The idea of the library OS is that the personality of the OS on which an application depends runs in the address space of the application. A small, fixed set of abstractions connects the library OS to the host OS kernel, offering the promise of better system security and more rapid independent evolution of OS components.We describe a working prototype of a Windows 7 library OS that runs the latest releases of major applications such as Microsoft Excel, PowerPoint, and Internet Explorer. We demonstrate that desktop sharing across independent, securely isolated, library OS instances can be achieved through the pragmatic reuse of networking protocols. Each instance has significantly lower overhead than a full VM bundled with an application: a typical application adds just 16MB of working set and 64MB of disk footprint. We contribute a new ABI below the library OS that enables application mobility. We also show that our library OS can address many of the current uses of hardware virtual machines at a fraction of the overheads. This paper describes the first working prototype of a full commercial OS redesigned as a library OS capable of running significant applications. Our experience shows that the longpromised benefits of the library OS approach-better protection of system integrity and rapid system evolution-are readily obtainable.

Many multithreaded concurrency platforms that use a workstealing runtime system incorporate a "cactus stack," wherein a function's accesses to stack variables properly respect the function's calling ancestry, even when many of the functions operate in parallel. Unfortunately, such existing concurrency platforms fail to satisfy at least one of the following three desirable criteria:• full interoperability with legacy or third-party serial binaries that have been compiled to use an ordinary linear stack, • a scheduler that provides near-perfect linear speedup on applications with sufficient parallelism, and • bounded and efficient use of memory for the cactus stack. We have addressed this cactus-stack problem by modifying the Linux operating system kernel to provide support for thread-local memory mapping (TLMM). We have used TLMM to reimplement the cactus stack in the open-source Cilk-5 runtime system. The Cilk-M runtime system removes the linguistic distinction imposed by Cilk-5 between serial code and parallel code, erases Cilk-5's limitation that serial code cannot call parallel code, and provides full compatibility with existing serial calling conventions. The Cilk-M runtime system provides strong guarantees on scheduler performance and stack space. Benchmark results indicate that the performance of the prototype Cilk-M 1.0 is comparable to the Cilk 5.4.6 system, and the consumption of stack space is modest.

This paper revisits an old approach to operating system construction, the library OS, in a new context. The idea of the library OS is that the personality of the OS on which an application depends runs in the address space of the application. A small, fixed set of abstractions connects the library OS to the host OS kernel, offering the promise of better system security and more rapid independent evolution of OS components.We describe a working prototype of a Windows 7 library OS that runs the latest releases of major applications such as Microsoft Excel, PowerPoint, and Internet Explorer. We demonstrate that desktop sharing across independent, securely isolated, library OS instances can be achieved through the pragmatic reuse of networking protocols. Each instance has significantly lower overhead than a full VM bundled with an application: a typical application adds just 16MB of working set and 64MB of disk footprint. We contribute a new ABI below the library OS that enables application mobility. We also show that our library OS can address many of the current uses of hardware virtual machines at a fraction of the overheads. This paper describes the first working prototype of a full commercial OS redesigned as a library OS capable of running significant applications. Our experience shows that the longpromised benefits of the library OS approach-better protection of system integrity and rapid system evolution-are readily obtainable.